Field of the Disclosure
Embodiments of the disclosure relate to a quantum rod, and more particularly, to a quantum rod being capable of emitting short wavelength light and a method of fabricating the same.
Discussion of the Related Art
Recently, as the society has entered in earnest upon an information age, a field of display devices that represent all sorts of electrical signals as visual images has developed rapidly. Flat panel display device, such as a liquid crystal display (LCD) device, a plasma display panel (PDP) device, a field emission display (FED) device and an organic light emitting diode (OLED) device, has been introduced.
On the other hand, use of a quantum rod to the display device is researched or studied. Since the quantum rod has high emitting efficiency and excellent reproducibility, the quantum rod can be applied to various uses. For example, applications of the quantum rod to an emitting diode for lightings and a light source or other element for the LCD device are researched.
The quantum rod includes a nano-sized core particle of II-VI, III-V, I-III-VI or IV-VI semiconductor particle and a shell covering the core particle. In addition, the quantum rod further includes ligands for dispersion.
Since extinction coefficient and quantum yield of the quantum rod is very large in comparison to general dye, the quantum rod emits strong fluorescent light. In addition, by controlling a diameter of the quantum rod, a wavelength of light emitted from the quantum rod can be controlled.
The quantum rod emits linearly-polarized light. In addition, the quantum rod has an optical property is capable of controlling emission by outer electric field is applied. This may be referred to as stark effect. Accordingly, the optical efficiency of the display device can be improved by the optical property of the quantum rod.
On the other hand, to use the quantum rod for the display device, quantum rods for emitting red, green and blue lights. However, the quantum rod being capable of emitting the red light is only developed.
The quantum rod including CdSe core and CdS shell emits the red light. This quantum rod may be referred to as a CdSe/CdS quantum rod. Referring to FIG. 1, which illustrates an emission principle of the CdSe/CdS quantum rod, the CdSe/CdS quantum rod has the energy gap (Eg) of about 1.6 eV. As a result, the CdSe/CdS quantum rod emits the red light in about 775 nm wavelength.
As mentioned above, the wavelength of the emitted light from the quantum rod can be controlled by a size of the core (i.e., the diameter of the core). However, even though the size (diameter) of the core is minified to be 3˜7 nm, the wavelength of the emitted light from the quantum rod can be extended within a range of 500˜650 nm.
Accordingly, it is impossible to provide short wavelength light by the related art quantum rod.